1 * 18/17: (18/17 + 2 * 7/11) = 99/218,

1) 2 * 7/11 = 14/11 = 1 3/11,

2) 18/17 +1 3/11 = 18/17 + 14/11 = 198/187 + 238/187 = 436/187 = 2 62/187,

3) 18/17 : 2 62/187 = 18/17 : 436/187 = 18/17 * 187/436 = 99/218